1. Field of the Invention
The present invention relates to a process for producing cationic synthetic rubber latexes.
2. Description of the Prior Art
Most conventional synthetic rubber latexes are produced using anionic or non-ionic emulsion polymerization systems. They are devoid of oriented adsorbency to polyvalent metal ions, cement, glass, metals, aggregates, etc., and thus cannot be used to modify cement, to rubberize asphalt, or for adhesion to inorganic materials or to form films on metal surfaces.
As cationic latexes, polychloroprene latexes are now commercially available, but the emulsifier used to produce the same comprises a quaternary ammonium salt which renders the emulsion so stable that products formed therefrom do not easily solidify. Accordingly, when products containing such emulsion are applied, for example, to the surface of an inorganic material, e.g., to an aggregate or a metal, they must be force dried using heat or subjected to conventional evaporation for long periods of time. These latexes have the further drawback that the emulsifiers remain stable in a rubber film formed therefrom to adversely affect water-resistance and chemical resistance of such a film.
As a process for producing cationic rubber latexes, it has been proposed to add cationic emulsifiers to latexes manufactured by anionic or non-ionic polymerization. While the latexes can thus be rendered largely cationic by the use of a large amount of a cationic emulsifier, they still retain a partial anionic or non-ionic character with, accordingly, a partial retention of the disadvantages set forth above.